Dispersion correction in cylindrical Hopkinson pressure bars

Dispersion correction in Hopkinson pressure bars according to:

[1] Tyas A and Watson A J 2001 An investigation of frequency domain dispersion
correction for pressure bar signals Int. J. Impact Eng. 25 87–101

Uses function (2) to calculate the velocity ratio either directly or via
look-up tables from:

[2] Bancroft D 1941 The Velocity of Longitudinal Waves in Cylindrical Bars
Phys. Rev. 59 588-93

Based on:

[3] A MatLab script for phase angle and amplitude correction of pressure
bar signals. Dr Andrew Barr
https://blast.shef.ac.uk/software/dispersionm-matlab-script-phase-angle-and-amplitude-correction-pressure-bar-signals